A magneto-resistive (mr) device for reading at least one of a legacy data and a present data magnetically recorded on at least one legacy track and a least one present track, respectively, is provided. The device comprises first and second mr elements, and first, second, and third permanent magnets. The first mr read element is positioned between the first and the second permanent magnets to stabilize the first mr read element while reading the legacy data from the media. The second mr element is positioned adjacent to the second permanent magnet and configured to read the present data from the media. The third permanent magnet is positioned adjacent to the second mr element and opposite to the second permanent magnet. The second and the third permanent magnets cooperate with each other to stabilize the second mr read element while reading the present data from the media.
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1. A magneto-resistive (mr) device for reading at least one of a legacy data and a present data magnetically recorded on at least one legacy track and a least one present track, respectively, on magnetic media, the device comprising:
a first mr read element configured to read the legacy data from the media;
first and second permanent magnets for positioning the first mr read element therebetween to stabilize the first mr read element while reading the legacy data from the media;
a second mr read element positioned adjacent to the second permanent magnet and configured to read the present data from the media; and
a third permanent magnet positioned adjacent to the second mr read element and opposite to the second permanent magnet such that the second and the third permanent magnets cooperate with one another to stabilize the second mr read element while reading the present data from the media;
wherein the at least one legacy track is arranged to a width that is greater than a width of the at least one present track.
12. A method for reading at least one of a legacy data and a present data magnetically recorded on at least one legacy track and a least one present track, respectively, on magnetic media, the method comprising:
reading the legacy data from the media with a first mr read element;
positioning the first mr read element between first and second permanent magnets so that the first and second permanent magnets stabilize the first mr read element while reading legacy data from the media;
reading the present data with a second mr read element;
positioning the second mr read element adjacent to the second permanent; and
positioning a third permanent magnet adjacent to the second mr read element and opposite to the second permanent magnet such that the second and the third permanent magnets cooperate with each other to stabilize the second mr read element while reading the present data from the media;
wherein the at least one legacy track is arranged to a width that is greater than a width of the at least one present track.
18. A magneto-resistive (mr) device for reading at least one of a legacy data and a present data magnetically recorded on at least one legacy track and a least one present track, the device comprising:
a first mr read element including a first set of characteristics configured to read the legacy data from the media;
at least one first permanent magnet positioned about the first mr read element to stabilize the first mr read element while reading the legacy data from the media;
a second mr read element including a second set of characteristics that is different from the first set of characteristics of the first mr read element, wherein the second mr read element is positioned adjacent to the at least one first permanent magnet and is configured to read the present data from the media; and
at least one second permanent magnet positioned adjacent to the second mr read element and opposite to the at least one first permanent magnet such that the at least one first permanent magnet and the at least one second permanent magnet cooperate with one another to stabilize the second mr read element while reading the present data from the media
wherein the at least one present track is arranged to a width that is less than a width of the at least one legacy track.
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1. Technical Field
The embodiments of the present invention generally relate to a hybrid trackwidth read element.
2. Background Art
Driven by a continuing demand for ever-increasing amounts of information storage in an ever-decreasing volume, there is an ongoing trend to reduce dimensions in nearly all magnetic recording systems. Included in this trend is the width of the data track. Therefore, data tracks that were recorded at one time in a given older system (referred to herein as legacy data) are generally wider than data tracks that are recorded at a later time in newer systems (referred to herein as present data). Yet, at times, it may be necessary to read legacy data from similar media tape, floppy disk, rigid disk, or magnetic strip (e.g., such as on a credit card) based families. Legacy data may be stored on media along with present data. By design, the magnetic media forms regions of magnetization that are generally of similar magnetization orientation. A magnetic transition is formed when these regions have generally opposing magnetization directions to each other. The legacy data and present data are generally stored on the media as magnetic transitions spaced from each other by varying distances. Legacy data, in general, is written at a different trackwidth on the media than that of present data. Often times, the trackwidth of the legacy data on the media is greater than the trackwidth of present data.
Due to such a condition, data readers for reading present data on the media are generally configured to read such data at a narrow trackwidth as opposed to the trackwidth needed to read legacy data. In the event the trackwidth that is preferred for reading the present data is too narrow, such a condition may present a signal-to-noise issue while reading legacy data as the present data reader may not be able to sample enough of the media. As noted above, the media may be a mixture of isolated (e.g., not exchange coupled) particles and comprise legacy data. The particulate nature of the magnetic media is desired to increase the signal-to-noise ratio. To compensate for the potential signal-to-noise issues with a present data reader that is not able to sample enough of the media, a legacy data reader may be added to a media read device that is configured to read the legacy data at greater trackwidths. The media read device may also include a present data reader to read the present data from the media at narrow trackwidths. Such an implementation generally incurs significant cost for the media read device.
In one embodiment, a magneto-resistive (MR) device for reading at least one of a legacy data and a present data magnetically recorded on at least one legacy track and a least one present track, respectively, is provided. The device comprises first and second MR elements, and first, second, and third permanent magnets. The first MR read element is positioned between the first and the second permanent magnets to stabilize the first MR read element while reading the legacy data from the media. The second MR element is positioned adjacent to the second permanent magnet and configured to read the present data from the media. The third permanent magnet is positioned adjacent to the second MR element and opposite to the second permanent magnet. The second and the third permanent magnets cooperate with each other to stabilize the second MR read element while reading the present data from the media.
In another embodiment, a method for reading at least one of a legacy data and a present data signal magnetically recorded on at least one legacy track and a least one present track, respectively, on magnetic media is provided. The method comprises reading the legacy data from the media with a first MR read element. The method further comprises positioning the first MR read element between first and second permanent magnets so that the first and second permanent magnets stabilize the first MR read element while reading legacy data from the media. The method further comprises reading the present data with a second MR read element. The method further comprises positioning the second MR read element adjacent to the second permanent magnet. The method further comprises positioning a third permanent magnet adjacent to the second MR read element and opposite to the second permanent magnet such that the second and the third permanent magnets cooperate with each other to stabilize the second MR read element while reading the present data from the media.
In another embodiment, a magneto-resistive (MR) device for reading at least one of a legacy data and a present data magnetically recorded on at least one legacy track and a least one present track is provided. The device comprises first and second MR read elements, at least one first permanent magnet, and at least one second permanent magnet. The first MR read element includes a first set of characteristics and is configured to read the legacy data from the media. The at least one first permanent magnet is positioned about the first MR read element to stabilize the first MR read element while reading the legacy data from the media. The second MR read element includes a second set of characteristics that is different from the first set of characteristics of the first MR read element. The second MR read element is positioned adjacent to the at least one first permanent magnet and is configured to read the present data from the media. The at least one second permanent magnet is positioned adjacent to the second MR read element and opposite to the at least one first permanent magnet such that the at least one first permanent magnet and the at least one second permanent magnets cooperate with each other to stabilize the second MR read element while reading the present data from the media.
The embodiments of the present invention are pointed out with particularity in the appended claims. However, other features of the various embodiments will become more apparent and will be best understood by referring to the following detailed description in conjunction with the accompany drawings in which:
As required, detailed embodiments of the present invention are disclosed herein. However, it is to be understood that the disclosed embodiments are merely exemplary of the invention that may be embodied in various and alternative forms. The figures are not necessarily to scale, some features may be exaggerated or minimized to show details of particular components. Therefore, specific structural and functional details disclosed herein are not to be interpreted as limiting, but merely as a representative basis for the claims and/or as a representative basis for teaching one skilled in the art to variously employ the present invention.
Referring now to
The tape 16 is positioned about the reader 12 and the permanent magnets 14a and 14b. A first lead 18 is coupled to the permanent magnet 14a. A second lead 20 is coupled to the reader 12. A third lead 22 is coupled to the permanent magnet 14b. The reader 12 is configured to read magnetically recorded data from the tape 16. To read legacy data, from the tape 16, the leads 18 and 22 are electrically coupled together such that, in one embodiment, a fixed current passes through reader 12, the pair of permanent magnets 14a and 14b and through the leads 18 and 22. In general, the MR element 12 changes resistance in response to the magnetic data stored on the tape 16 thereby varying voltage in which the varying voltage is indicative of the data stream on the tape 16. The permanent magnets 14a and 14b are generally configured to stabilize the MR element 12. For example, the permanent magnets 14a and 14b are magnetically coupled to the MR read element 12 and apply a fixed field thereby properly aligning the MR read element 12 and ensuring that the MR read element 12 maintains a desired magnetization configuration. The configuration provided when reading legacy data generally provides for a stable response from the MR read element 12 since both sides of the MR read element 12 are magnetically coupled to the permanent magnets 14a and 14b due to the coupling of the leads 18 and 22 together.
To read present data stored on the tape 16, the leads 18 and 20 are electrically coupled together such that current passes through the reader 12, the permanent magnet 14a and the leads 18 and 20. Again, the voltage may vary based on the change of resistance exhibited by the MR read element 12 whereby the varying voltage may be indicative of the present data on the tape 12. Although the entire MR element 12 responds to the tape 16 by changing its resistance, the varying voltage that is indicative of the magnetization of the media is only induced in an “active region” of the MR read element 12. The active region of the MR read element 12 is the region disposed between the leads 18 and 20. By coupling the leads 18 and 20 together to obtain the present data from the tape 16, such a condition may leave the active region of the MR read element 12 in a less stable state. By magnetically coupling a single permanent magnet 14a to the MR read element 12 via the leads 18 and 20, the permanent magnet structure may be in an asymmetric state with respect to the MR read element 12. Such a condition may lead to Barkhausen noise issues. Due to the exchange coupled nature of the MR read element 12, an additional noise source is associated with the adjacent MR material between leads 20 and 22. This could occur through the changing magnetic orientation of the adjacent MR material between leads 20 and 22 being exchange coupled to the portion of the MR read element 12 between leads 18 and 20 causing unwanted signal degradation while reading present data.
Referring now to
Referring now to
Media (tape or disc) 56 having data in the form of magnetic properties are stored thereon. The media 56 is positioned about the MR read elements 52a and 52n and the permanent magnets 54a-54n. The MR read elements 52a and 52n and the permanent magnets 54a-54n may contact the media 56 or be separated from the media 56 by an air bearing surface (ABS) (not shown). A first lead 58 is coupled to the permanent magnet 54a. A second lead 60 is coupled to the permanent magnet 54b. A third lead 62 is coupled to the permanent magnet 54n.
In general, the MR read element 52a is generally configured to read present data from the media 56. The MR read element 52b is generally configured to read legacy data from the media 56. In contrast to the device 10 of
For example, to read present data from the tape 56, leads 58 and 60 may be electrically coupled such that any varying voltage generated by the MR read element 52a is passed through the permanent magnets 54a and 54b and the leads 58 and 60. The varying voltage is generally indicative of the data stored on the media 56 based on recent or current generation recording methods. The permanent magnets 54a and 54b stabilize the MR read element 52a. To read legacy data from the tape 56, leads 60 and 62 may be electrically coupled such that any current generated by the MR read element 52b is passed through the permanent magnets 54b and 54n and the leads 60 and 62. The varying voltage is generally indicative of the data stored on the media 56 in accordance to older or legacy generation recording methods. The permanent magnets 54b and 54n stabilize the MR read element 52n. In such a configuration, each MR read element 52a and 52b is stabilized due to the presence of the permanent magnets 54a-54n on each side of the each MR read element 52a and 52b.
The permanent magnets 54a-54n may be made of an alloy of cobalt (Co), chromium (Cr) and platinum (Pt). The permanent magnets 42a-54n may each have a magnetization of 460 emu/cm3. Each permanent magnet 54a-54n may have a different or similar thickness (e.g., TH1, TH2, and TH3) from one another as shown in
Because a wider MR element generally produces more signal, each MR read element 52a and 52b may have different widths in order to optimize the signal to noise for the legacy and the present generation read as shown in
As is shown in
Each MR read element 52a-52b generally includes an active sensing layer that rotates in the presence of an externally applied field from the magnetic media 56. The thickness of the active sensing layer is between 20 and 400 Angstroms of Ni80Fe20 effective thickness. The thickness of Ni80Fe20 generally corresponds to a magnetization-thickness product (or Mrt) between 1.6 mA and 32 mA for each MR read element 52a-52b. The magnetization-thickness product for each MR read element 52a-52b may be similar to one another or different from one another.
The MR read elements 52a-52b may also each be arranged to include different or similar materials from one another, or different or similar sensing mechanisms from one another (e.g., AMR, GMR, or TMR). An AMR read element is generally comprised of a seed layer which is typically Ta; a soft adjacent layer, which is typically a magnetically soft alloy such as Co90Zr5Mo5; a non-magnetic spacer layer that may be comprised of Ta; and an active magnetic read layer that may be comprised of Ni80Fe20. A GMR read element is generally comprised of a seed layer that may be comprised of Ta or NiFeCr; an antiferromagnetic layer that may be comprised of a Mn-based antiferromagnet such as Pt49Mn51 or Ir20Mn80; a pinned layer, that may be comprised of Co90Fe10 or (Co90Fe10)80B20; a material providing antiferromagnetic coupling such as Ru; a reference layer that may be comprised of Co90Fe10 or (Co90Fe10)80B20; a non-magnetic spacer layer that may be comprised of Cu; a free layer that may include a bilayer material of Co90Fe10 or (Co90Fe10)80B20 and Ni80Fe20. A TMR read element may be identical to the GMR structure, but may remove the Cu layer and replace such a layer with an alumina (AlOx) or MgO insulating layer. By independently controlling the stripe height, widths, thickness, magnetization-thickness product, materials, and/or sensing mechanism for each MR read element 52a and 52b, such control may provide for optional performance for the MR read element 52a while reading present data and for the MR read element 52bwhile reading legacy data.
While embodiments of the invention have been illustrated and described, it is not intended that these embodiments illustrate and describe all possible forms of the invention. Rather, the words used in the specification are words of description rather than limitation, and it is understood that various changes may be made without departing from the spirit and scope of the invention.
Nibarger, John P., Partee, Charles C.
Patent | Priority | Assignee | Title |
10102870, | Dec 13 2013 | Seagate Technology LLC | Shielding and electrical contact design for devices with two or more read elements |
9218823, | Feb 25 2014 | Seagate Technology LLC | Read head with multiple reader stacks |
9361910, | Jul 03 2014 | Seagate Technology LLC | Leads coupled to top and bottom reader stacks of a reader |
9396745, | Mar 07 2014 | Seagate Technology LLC | Multi-sensor reader with different readback sensitivities |
9401163, | Jul 03 2014 | Seagate Technology LLC | Multi-stack reader with split middle shield |
9406321, | Feb 27 2014 | Seagate Technology LLC | Read head with multiple reader stacks |
9524737, | Dec 13 2013 | Seagate Technology LLC | Shielding and electrical contact design for devices with two or more read elements |
Patent | Priority | Assignee | Title |
3967368, | Oct 11 1972 | International Business Machines Corporation | Method for manufacturing and using an internally biased magnetoresistive magnetic transducer |
4851944, | Feb 17 1987 | Seagate Technology, INC | Ganged MR head sensor |
5107385, | Nov 16 1989 | Applied Magnetics Corporation | Read head assembly for multiple-width tracks |
5331492, | Sep 27 1990 | Kabushiki Kaisha Toshiba | Magnetic disk system having a magnetoresistive head provided therein |
7106544, | May 09 2003 | Advanced Research Corporation | Servo systems, servo heads, servo patterns for data storage especially for reading, writing, and recording in magnetic recording tape |
7133264, | Sep 13 2002 | Western Digital Technologies, INC | High resistance sense current perpendicular-to-plane (CPP) giant magnetoresistive (GMR) head |
20050128654, | |||
20070285838, |
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